Telephone-exchange system.



A. E. LUNDELML. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED SEPT- 22.19l6.

Patented Mar. 26, 1918.

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Lom. Patented Mm. 2u, 1918.

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A. E. LUNDELL.` TELERHONE- EXCHANGE SYSTEM.

APPLICATION FILED SEPLZZ. I9I6.

Patented Mar. 26, 1918..

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APPLICATION FILED SEPTA 22, l9l6.

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.ALBEN E. LUNDELL, OF NEW YORK, N. Y., ASSIGNOR TC WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., .A CORPORATION OF NEW YORK.

'TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Mar. 26, 1918.

Application filed September 22, 1916. Serial No. 121,561.

change systems, and more particularlyl to improvements in automatic or semi-automatic telephone exchanges. Y

It is the objectA of this invention to provide a new and improved arrangement for controlling selectively operable switching devices employed in automatic or semi-automatic telephone exchanges. y

A reduction in cost of selector and con nector switches employed in automa-tic and semi-automatic telephone exchanges, is' attained, within certain limits, by increasing the capacity of the switches. It has been found, for instance, that a `tive hundred pointl switch, that is to say, a switch the terminal bank of which contains tive hundred sets of terminals, may be advantageously used in automatic telephone systems.

In systems in which live hundred point switches are employed, the sending or con trolling device, by means of which the set ting or this switch is controlled, must 4be equipped with an arrangement to translate the impulses, This is necessary because in order to set up the called subscribers Vnumber, which is given in accordance with the decimal numerical system. of indication, the senders must be arranged in accordance with the saine numerical system ot" indication. It' the number of the called line is, for instance, 1537, thenthe operator in a Semi- Y automatic exchange will depress sender keys l, 5, 3 and 7 in the thousands, hundreds, tens and units rows of keys.

ifissuming that the capacity of the eX- change is ten thousand lines, each of the tive hundred point selector switches must have access to all tlielines through tive` hundred point connector switches. To this endthe selector' switches are equipped with five sets ot brushes and the terminal bank of each ci these switches is di 'idcd intoA tive levels, cach level being served byone of the brushes. l `h us,'tl irough eachlevel access may be had t0 two thousand lines.

Supposing that the tiattic conditions areV such that one hundred trunks are su'liicient to give service to two thousand lines, each level contains four groups ot' terminals, and in each of these groups twenty-tive terminals are provided for these trunks. Taking the first level of one hundred terminals, the trunks leading from the tirst group are eX- tended to connectors containing the line terminals of the subscribers lines 0000 to 0&99;

the trunks leading from the second group are extended to connectors containing the line terminals 0500 to 0999; from the third group the trunks lead to connectors containing line terminals 1000 to 14e 9; and from the fourth group the trunks lead to connectors containing line terminals 1.500 to 1999. If line No. 1537 iS desired, the brush having access to the first level of terminals must be selected. In view of the fact, however, that the thousands key depressed was key 1 and this key being the second in the row atteikey 0 will usually cause the sending of two impulses, the sender apparatus must be so provided that although the No. 1 key is depressed, only one impulse will be sent out to select the first set ot brushes. Furthermore, in view of the iact that the line 153'? terminates in a connector accessible through trunks terminating in the fourth row ot the first level of terminals or the selector' switch, and the hundreds key depressed was number 5; that is to say, adapted to cause thesend ing of six impulses, it will be necessaryv to translate these six impulses in such a manner as to cause the selector switch to take only tour steps.

These translating arrangements must be permanent fixtures of thc exchange, because it could not be left to the operator to calculate what kind of a ninnerical digit should be Vsent out, instead ot the numerical digit representing the called subscribens line.

In commercial telephone exchanges it may be necessary to control by means ot' the sending apparatus, not only selector switches of the above described type, but also scleclively operable switching devices which Thisyhowever, would be an expensive `ar-frangement.

According to the main features of the Vpresent invention a sending device adapted i tov control switches arranged in accordance` with another numerical designation than the decimal, and provided with translating means, may also be used for setting selectively opera-ble switching devices which must be adjusted in accordance with decimal numerical indication. Or in other woi'ds this invention provides automatic means for causing a switch to move toa 'po- 'sition corresponding in numerical designationV to that of its actuated controlling lmeans, such as a sender key, although` theL calling subscribers station, and a selector switch by means ot which the callingfline may be extended; Fig. 2 represents the 4circuits of a selector switch adapted to be operated by impulses translated atV the sending device; Fig. 3 represents selectively operable Y switching devices which may be reached through the selector shown'in Fig. 1 and which must be set in accordance with the decimal numerical indication; and Fig. l represents an operator-s sending or con-V trolling` device ior the selectively operable switches of the system. To show the complete circuit, Fig. 3 should be placed to the right, and Fig. l below Fig. 1. Fig. 2 should be placed below Fig. 3.

Only so much is shown of the circuits and apparatus as is necessary for an understanding of the invention. A. complete circuitarrangement for the selector switches shown in Figs. 1 and 2 may bek had from Patent No. 1,168,319 to A. E. Lundell. rIhese selector switches arepreferably of the sovcalled panel type, and are similar in structure to thev switch disclosed in Patent No. 1,123,696 to E. B. Craft and J. N. Reynolds.

Sequence switches 106, 212,307 and `4101,

' shown in Figs. 1, 2,3 and al. respectively, are

similar to the switchstructure described in Patent No. 1,127 ,808. The sequence switch contacts shown in Figs. 1, 2 and l and above the horizontal dotted line in Fig. 3, are controlled by the respective sequence switches, but for the salie of clearness, these contacts are indicated diagraminatically instead of in their structural relation to each other.

The selectively operable switching devices which must be set inV accordance with the Vdecimal indication of the called line are shownV below the horizontal dotted linein Fig. 3.V .The sequence switches 308, 320, 309, 310 and 311 are -of the same structure asrthe sequenceswitches ,above referred to, thezcon-I tacts controlled. by each ofthese switches l .Y front contact, a contact105andthe` power being shown within the dotted rectanglesiin switches the A operator whose sending-device is. shown in Fig. L1,;may causethe` iiidicationof-thefnumbeig of a calledaline at aV l B operators position. The lamps shown in the: rectangleV including the contacts of' switch 308, are lighted inthe various positions of this switch. The hundreds, tens and units indicator` switches 309, 310 and 311 control also lamps for indicatingthe number of the called line.V Oiilyone of the indicating lamps is shown adjacent tothese latter mentioned switches, the location 'of the other lamps being merely indicated at l contacts of such switches.

Itwill be obvious to'those skilled in the art that insteadot the disclosedV translating arrangement, other translating arrangements may be used withouty departing from the spirit of the present invention. would be necessitated, for instance, if other than five hundred point switches are used,

This j or if it is desired to control the counting f relays shown inFig. fl through so-called'register `controllers instead of' directly by 'the keys. Patent No. 1,168,319 discloses-such an arrangement. Patent No. 1,157 ,881 shows a translating` arrangement for two hundred point switches.v Obviously, if other translating arrangements are used, the arrangements of the contactsl of the indicator switches shown in Fig.` 3' mustV also be changed in accordance with tlijepresent iiiventioii. It will be furtherfobvious that instead ofthe sending. apparatus, the selectorA switches, the sequence switches and the number indicators described in the mentioned patents, apparatus of widely varying character may be employed without departing from the spirit of the V present invention. Instead of indicatorswitches shown in Fig. 3 for instance, step-by-stepone hundred `or ten. point switches may be employed.

A full understanding of the present invention may be had from the following',detailed description. and the appended claims. Y

A subscriber at station desiring to initiate a call removes'his'receiver from the switchhoolr, whereupon relay 'LR becomes energized and causes the actuation of a calling lamp CL. An A operator, whose tele phone head set is shownat 101,`noticing the ioo` lamp CL'lighted, inserts aplug 102 intoVV ananswering jack 103 in which the calling subscribersline terminates.V Relay SR becomes energized througlithe calling line circuit'and a circuit is v,closed from ground, through thewinding; of a relay 10%, the sleeve contacts ofplug102 and jackV 103, and

kthe winding of a cut-oft l(relay CO to grounded battery. The' cut-off lrelayv dis, connects, theliiie relay, whereup lamp CL is extinguished. Relay 104 closes` a circuit from ground, through its Varmature and isoV Vgrounded battery.

battery, for moving this sequence switch out of position 1, and under the control of its normal spring 107 into position 2.

As soon as the sequence switch 106 reaches position 21a circuit is established from ground, through a sequence switch contact 108, a conductor 109, a contact 400 ot' a sequence switch 401, 4and the winding of a relay 402 to grounded battery. Relay 402 closes a locking circuit for itself vfrom 4 grounded battery, through its winding, a

sequence switch Contact 403, the right-hand :front contact and armature vof relay 402, conductor 404 and a sequence switch contact 110 to ground. A circuit is also closed from ground, left-hand front contact and armature of relay 402, a contact 405 and the power magnet of sequence switch 401 to grounded battery, for. moving this sequence switch out of position 1 intov position 3.

By depressing a listening-key 111 the A operator connects her telephone set 101 into telephonie association with the calling subscriber, and having` learned from him the called subscriber-s number, will set up such number on her keyboard, shown in Fig. 4. Let us assume that the calling subscriber desires to obtain a connection with a line associated with an ofice into which trunks 112, 113, 114 lead. -r-is these trunks terminate in the first group or contacts of an oflice selector 115, the operator will depress an oflice key 406, having already moved the sequence switch 401 out of position 3 and into position 4 by a circuit established through a start key 407 and a sequence switch contact 408.

In position 4 o1 sequence switch 401 a fundamental circuit isclosed troni grounded battery, through the winding of relay 116, sequence switch contact 117, conductor 118, sequence switch contact 409, the outer armature and back contact ci the upper counting relay 0, the windings of a stepping relay 410, conductor 411 and a sequence switch contact 119 to lground. Relay 116 closes a locking circuit l'or itseliE through its lei''t-haiid :trent cont-act and armature and a sequence switch contact 120. Relay 11.6 also closes a circuit from ground, right-hand :front contact aiidarinature of relay 116, a sequence switch 121, a conductor 136 and the power magnet of sequence switch 106 to Sequence switch 106 moves into position 3 and closes a circuit from ground, through the right hand armature and liront contacto-t relay 116, a con` tact 121, and the winding of an rip-drive magnet 122 to grounded battery. By at-V tracting its armature, magnet 122 presses a brush rod 123 carrying wipers 124, 125, 126 and a eoiiiiiiutatcr brush 128 against a roller 127 constantly rotating,I in the direction indicated by the arrow, whereupon the wipers will be caused to more over a terminal bank 129, and the brush 128 over a coiniiiutator plate 131.

Relay 410 closes a circuit from ground through its armature and front contact, a sequence switch contact 412, the contactoi key 406, conductor 413, the winding ot the lower counting relay 0, and a conductor 414 to grounded battery. Upon the energizatioii. of the lower counting relay 0 a circuit is closed from ground through a sequence switch contact 415, the armature and front contact of the lower counting relay 0, and the windings of the upper and lower counting relays 0, and conductor 414 to grounded battery. Due to the shunt path closed from the winding of the lower counting relay 0 at the armature. and front contact of stepping relay 410, the upper counting relay 0 cannot become energized. As soon, however, as commutatoi brush 128 contacts with a conducting segment 130 of commutator plate 131, a shunt is closed around relay 410 from ground through brush 128, conducting` segment 130, a conductor 132, and sequence switch contacts 133 and 120, to the winding of relay 116. The stepping relay 410 becomes deenergized and removes the short circuit from around the winding of the upper counting relay 0. The upper counting relay 0 then becomes energized and opens the funda mental circuit atits outer armature and back contact. It closes also a Circuit troni ground, through sequence switch contact 416, its inner armature and front contact, and the winding of the power magnet of sequence lswitch 401 to grounded battery, for moving the sequence switch out of position 4 intoV position 6. 1While the sequence switch is moving troni position 4 to position 6, the counting relays are unlocked.

soon asd brush 128 encounters :in insulated segment 134, removing thus the ground from the winding ot relay 116, this relay becomes denergized, and assuming that the first trunk in this group is idle, a circuit is closed troni ground through the rightd'iand armature and back contact of relay 116, sequence switch contact 135, conductor 136, and the power magnet ot sequence switch 106 to grounded battery.` for moving this sequence switch out of position 3 into position 11.

When sequence switch 106 reaches position 8 a circuit is closed from ground, through sequence switch contact 140, wiper 126, terminal 141, conductor 114, and the wi riding of a relay 200 to grounded battery. Relay 200 becomes energized and controls the guarding et trunk 112, 113, 114 in the well-known manner. Wl nen sequence switch 106 reaches position 11 and sequence Switch 401 position 6, the fundamental circuit is eX tended for controlling a group selector switch 201.

Let us suppose that this exchange has U pon the opening oit the fundamental circuit and asV capacity to accommodate ten thousand lines. Two hundred connector switches (not shown) to which the calling line'may be eX- tended through selector switch 201, will be provided, each of these connector switches containing. the termina-ls of five hundred lines. The terminal bank 202 of the selector comprises five hundred sets of contacts in which trunks leading to the connector switches terminate. Each of the selector switches, fty of such switches being provided for a ten-thousand line exchange, has an access to all the lines through the connectors;

,Theterminal bank of the selector 201 is div-ided into live levels (only a few of the levels being shown) each containing one hundred terminals, in which terminate a sufficient number of trunks,A preferably one hundred in each, for accommodating the traffic withA two thousand lines tol which access may be had through each of these levels of terminals. ln order to make'possible the seizure of a set of terminalsin any onefof the selector terminal levels, five sets of brushes 203, 204, 205, 206, 207 are provided on a brush rod 201, of the selector. Supposingthat the called subscribers number is 1537, the operator after having controlledl the setting of the oiiice selector 115,

depresses key No. l in the thousands, key No.5 in the hundreds, key No. 3 inthe tens, and keyilo. 7 in the units rows of keys.

The first ofthe connectors has access to the subscribers lines Nos. 0000-0499, and the fourth connector has access to lines 1500- 1999; The four connectors serving lines 0000-1999 may be reached through the twenty-five trunks terminating in the first group of the terminal bank 202. It will be necessary therefore to operate or trip brushes 203 and to cause them to perform four steps. ln View ofv the fact that the operator depressed the thousands key No. 1v and the hundreds key No. 5, it' is necessary that the ltwo and siX impulses which would be usually received by the counting relays upon the depression of similar keys, be translated into one and'four impulses. This translation is accomplished by wiring the thousands and hundreds keys in a manner shown in Fig. 4 of the drawings.

The left-hand contacts 420 and 421 of the thousands keys 0 and 1 are wired to the 0' counting relays; that is to say, no matter whether 0 or 1 is thethousands designation of the called line, the first set of brushes will be selected, because these are the brushes that may select trunks leadino to connectors in which the subscribers lines from 0000 to 1999V terminate. In a similar manner theVA left-hand contacts of thev thousandskeys 2,73*;4, 5; 6,7 ;zand8, 9 are wired to counting relays 1, 2, 3 and 4 respectively. The rightfhandcontact 422 of the thousands key No. O'iswired to the hundreds keys in one row with key 424. ,The right-hand con* tact 428 ofthe thousands keyv No; lis wired to the hundredskeys in one vrowwith key 425.V Similarly the right-hand contactsy of the even number thousands keys are wired toY the hundreds keys in one row with key 424, and the right-hand contactsof the odd number thousands keys are' wired `to the` hundreds keys in one row with key 425. The contacts of the hundreds keys 0 to 4 in one row with key 424 are wired tothecounting relays 0, and the contacts of keys 5 9 in this row are wired to counting relays 1.

The contacts of the hundreds keys 0 to 4 in one row with key 425 are wired tocounting relays 2, and the contactsofkeys to 9 in this row to counting relays 3. The contacts of the hundredskeys in one row withy key 426 are wired as follows: keys 0 and 5 to No. 0, keys 1 and 6 to No. 1, keys 2 and 7 to No. 2, keys 3 andS to'NofB, and keys/1 and 9 to No. 4,- counting relays. .The tens and units-keys are wired in numerical order toV the counting relays.

The fundamental circuit above referred to may be traced as follows: from grounded battery, throughthe winding ofI a relay 210,V

a contact 211 of a sequence switch 212, con

ductor 112,- terminal 142, wiper 124, a sequence switch contact V143, conductor 118,

sequence switch contact 409, the outer arma# ture and Vback contact ofV upper 04 coimtingl contact 214 and the power magnet of sequence switch 212 to groundedv battery, for

moving this sequence switch out of position 1 and intoposition 2.

ln position 2 of sequence switch 212 a circuit is closed fromv ground through the left-hand armature and lfront .contact offre-` lay 210, a sequence` switch contact 215 andV the winding of an updrive magnet 216,-to

grounded battery. Under the control of the' updrive magnet all the wipers of selector` 201 and commutator brushes 217 and 218 are caused to travel in anupward direction.-

The brushes are normally held out ofl engagement with the contacts of terminals of bank 202, andk before these brushes reach in their travel a position below the first group of terminals of the level; they serve,

brush` 217 engages' a conducting. segment 4 Upon the energiaation ofthe steppinglrelay 410 a circuit is established from ground through the front contact and armature of this relay, a sequence switch contact 427, conductor t28, contact 121 of the thousands key 1, conductorV L129, the winding of the lower counting relay 0 and conductor 41d to grounded battery. The lower counting 'relay 0 upon energization, closes a locking relay 0. This relay by'opening its outer contact causes the denergization of relay 4.10 and closes through its inner contact a circuit for driving sequence switch 401 out of position 6 into position 8, causing thus the unlocking of the counting relays.

llllhen brush 217 ismoved into engagenentwith an insulated segment ofrconduoting segment 219, the circuit ot relay 210 is broken and the magnetl becomes de'energizcd. lUpon the denergization of relay 210 a cir cuit is closed from ground through the letthand armature and back contact of this re.- lay, contact 223 and the power magnet ot' sequence switch 212, to grounded battery, t'or moving this sequence switch out of position 2 into position 3. 1n this position ot the sequence switch a circuit is closed from ground through a sequenceswitch contact 22d and the winding of a trip magnet 225 to grouiull ed battery. This magnet becomes energized and yearses the rotation of a trip rod (not shown) by one step, whereby during the turthcr increment ofthe brushes, brushes 203 will be tripped into engagement with the contacts of the lirst level of the terminal bank. The tripped brushes are non' in a position to the lowest terminals ot ,theV

tirft level and the commutator brushes are in a position where'brush 218 engag \,s a ronducting segment at 226.

ln position 8 ofsequence switch 401 and position 3 of sequence switch 212 the fundainental circuit is re'stablished and relay L110 and 210 become again energized. Relay 210 closes a circuit through itsright-hand armature to lock up its winding, and a circuit trom ground through its lett-hand armature and front contact, and a contact`211l and the power magnet ot sequence switch 212 to grounded battery, for driving this sequence switch out ot position 3 into position d. The relay'sl() closes a circuit from ground, through its front contact and armature, sequence switch vcontact 430, conductor 131, the contact A123 ofthe thousands key 1, contact 4:32 ot' the hundreds key 5, conductor 433, the armature and back contact of the upper counting relay 3, the winding et the lower counting relay 3, and conductor L11st to grounded battery. rllhe lower counting relay upon energization, closes a locking circuit through sequence switch contact -115 and the windings ot the upper and lower counting relays 3. The upper1 counting relay 3 cannot become energized due to the shunt path closed at the liront contact ot the stepping relay el10. As soon, however, as brush 218 contacts with the conducting segment at 226 and connects thus ground through conductor 227 and sequence switch contacts 223 and to the winding ot relay 210, the stepping relay L10 becomes deenergized and removes the short-circuit ,trom the winding oit the uppervcounting relay 3, and this relay extends conductor L133 to the winding of the lower counting relay 2. The operation Voit the counting relays continues until upon the engagement of the conducting segment 230 by commutator brush 218, the stepping relay 110 is shunted the fourth time and the upper counting relay 0 becomes energized. sequence switch 401 is moved then out of position Sinto position 10, the relays 4:10 and 210 become denergizeth and the counting relays are unlocked.

The brush 218 engages the conducting segment at 226 and 230 `when the brushes 203 are just below the first and fourth groups of contacts in the terminal bank. As long, therefore, as the brush 218 engages conductinof segment 230, oround is connected through conductor 227 and sequence yswitch contacts 228 and 231, the right-hand armature, front contact and the winding of relay 210 to grounded battery, and this relay remains `locked up, although the fundamental circuit is open. As soon, however, as the brush 218 leaves the conducting segment and engages an insulated segment 230', this locking circuit is opened. Relay 210 becomes denergized and closes a circuit through its left-hand armature and back contact, contact 223 and the power magnet ol" sequence switch 212 to grounded battery, for moving this sequence switch out ot position t. Magnets 2.25 and 216 become deenergized, whereupon the tripping spindle is released to normal and the wipers 203 are stopped on the fourth row of terminals in the iirst group of bank 202.

Sequence switch 212 is moved from position i into position 16 under the control ot a normal s ring 212 and while moving through the internat-ediate4 positions, controls various circuits of selector 201, but in view ot the tact that the above description is deemed sutlicient to enable one skilled in the art to Aunderstand. the' arrangement for controlling the translation of the impulses, these circuits have not been disclosed in detail.

The

Supposing that the irst terminal. in the fourth row is idle, the sequence switch 212 closes in position 8 a guarding circuit through sequence switch contact 232 for preventing the seizure of the selected truulrby other selector switches.

The connector switch (not shown) which has been seized by selector 201 is similar in construction to the latter. Upon the extension of the trunk 112, 113 to the trunk leading to such connector switch, the zero or iirst set of brushes of such connector will be selected, because in position 10 of the sec Y. quence switch 401 a circuit is closed from 15 ground through the front contact and armature of relay 410, a sequence switchY Contact 435, conductor 436, contact 437 of the hundreds key 5, conductor 438 and the winding of the lower counting relay 0 to grounded battery. The trip magnet of the connector will move the trippingspindle (not shown) by `one step. The reason for this is that the subscribers line is in the lowest group .of terminals of the connector switch. The connector is caused to seize the Called sub- Y switch out of position 11 into position 16.`

When Ythe called subscriber answers, the supervisory relay SR becomes energized.

When disconnection is desired and both the calling and called subscribers cause the actuation of their respective supervisory relays, the A operator removes plug 102 from jack 103, causing the denergization of relays CO and 104. A circuit is then closed Vfrom ground, through the armature and back contact of relay 104, a contact 151 and the power magnet of sequence switch 106 to grounded battery, for moving this sequence switch out of position 16 into position 18. A circuit is then closed from ground through sequence switch contact 152 and the winding of a down-drive magnet 153 to grounded battery. This magnet becomes energized and by attracting` its armature presses brush rod 103 against theroller 154 constantly rotat- V ing in the direction indicated by the arrow.

' The wipers and the brush 128 of thev selector l115 are caused to travel in a downward direction, and when brush 128 engages a conducting segment 155, ground ,is connected through conductor 156, sequence switch contact 157, conductor 136, and the power magnet of sequenceswitch 106, to grounded battery. This Y Laconia sequence switch is moved out of position 18 into position l, whereupon magnet 153 becomes denergized.V v Y When wiper 126 leaves terminal 141,relay 200 becomes denergized yand closes a cir- Quit from ground through its armature and back, contact, a contact 240 and the power magnet of sequence switch 212 to grounded battery, for moving this sequence switch out of position 16 into position 18. VA circuit is then closed from ground through sequence switch contact 241, and the winding of a down-drive magnet242 to grounded battery. Under the controlof this magnet the wipers and brushes of selector 201 are brought to their `normal position.` When brush 218 reaches its normal position a circuit is closed fromV ground through brush 218, a conduct ing segment 243, conductor 2,44, Va Contact 245 and the power magnet of sequence s switch 212 to grounded battery, for Vdriving Y Y this sequence switch out of position'lS into position 1, whereupon magnet242 becomes denergized. The connector is releasedin a similar manner upon the restoration of selector 201. Let us'` suppose that the calling subi scriber at station desires to obtain a connection with a subscriber located at station 300, the line of whom may be seized bya B Y operator whose position apparatus is shown 9 in Fig. 3. The calling subscriber is asso! ciated with the A operator inthesame manner as above described, but this operator causes the setting of selector 115 onto a trunk such as 160, 161, 162 leading to the office in Vloo which the called line terminates, .and terminating ina B operators plug 301. The set-p Y ting of selector 115 is accomplished in the same manner as Vabove 'described with the difference that in order lto Vset the switch onto the desired terminal, the operator depresses the otiice key 450, causing the selector to take two steps. After the setting of selector 115 the sequence switch 401 is moved into position 6, and sequence switch 106 is 110 standing in position 11,. as above dcscribed. Upon the completed seizure of the trunk, a circuit is closedirom grounded battery, through the windingl of a ,relay 302, p

Vconductor 16.2, wiper, 126 and sequence 115 switch contact 14.0 to ground. Relay 302 bccomes energized. Another oircuitis closed from ground through asequence switch contact 303, conductor 161., brush-125, sequence Y Switch contact 144, conductor 411,V the'wind- 12o ings of stepping relay 410, the back contact andouter amnature `of thelupper counting relay 0, sequence switchcontact 409, conductor 118,V sequence switch contact 143, wiper 124, conductor 160, conductor 316, se- 1,25 quenceswitch contact 304 and the winding of a relay 305 to grounded'battery. This is the funda-mental circuit. Relay 305 closes a-locking circuit for itself through its-leftfhand armature and` front contact, anda circuit 13o from ground through its rightnhand armature and front Contact, a contact 306 and the power mag iet of sequence switch 307 to grounded battery, for moving this sequence switch out of position 1 andinto position 2.

Supposing that the number oi the line leading to station 300 is also 1537, the A operator depresses the saine thousands, hundreds, tens and units keys as in the above assumed case.

Upon the depression ot the thousands key 1, a circuit is closed from ground through the iront Contact and armature of stepping relay 410, sequence switch contact 427, conductor 428, contact 421 oit the thousands key, conductor 429, the winding of the lower counting relay 0, and conductor 414 to grounded battery. The lower counting relay becomes energized and closes a locking circuit for the upper and lower counting rclays 0, the ornier of which is shunted out by stepping relay 410.

in position 2`of sequence switch 307 a circuit is closed from grounded battery, through the power magnet of indicator 303, a sequence switch contact 312, and the righthand front contact and armature of relay 305 to ground. Under the control oi' its normal spring 313, indicator 308 is moved tromlposition to position 0. W hen it is moving through position N-1/2; that is to say, between positions N and 0, a circuit 1s closed from ground through indicator contact 314, sequence switch contact 315, conductor 316, and sequence switch contact 317 to the winding of relay 305, causing thus the shunting out of the stepping relay 410 in the same manner as has been described in connection with the selector switch V115. Upon the denergization of stepping relay 410 the upper counting relay 0 becomes energized. The fundamental circuit is then opened at the outer armature and back centact or' the upper counting relay 0, resulting in the denergization ot relays 410 and 305. Relay 305 closes a circuit from ground through its right-hand armature and back Contact, a contact 318 and the power magnet of sequence switch 307 to grounded battery, and under the control of its normal spring 319 this sequence switch is driven out of position 2 into position 3. rlhe circuit o indicator 308 is then interrupted at contact 312, and this indicator stops in position 0.

The energization ot the upper counting relay 0 causes also the movement of sequence switch 401 out of position 6 into position 8, and thus the unlocking of the counting relays. l/Vhen the sequence switch 401 reaches position 3, the fundamental circuit is reestablished, relay 305 locks up andcloses through its right-hand front contact and sequence switch 306 a circuit for moving sequence switch 307 out of position 3 into position 4. A circuit is closed from groundod battery through the power magnet of translator 320, sequence switch contact 322 and the rightshand front contact and armature of relay 305 to ground. Under the control of its normal spring 321 this translator is moved from position to position.

Upon the renergization of stepping relay 410 a circuit is closed from ground, through the front contact and armature of this relay, sequence switch 430, conductor 431, contact 423 oit the thousands key, contact 432 of the hundreds key 5, conductor 433, the armature and back contact ot' the upper counting relay 3, the winding of the lower counting relay 3, and conductor 414 to grounded battery. The lower counting relay 3 becomes energized and the upper counting relay 3 remains shunted until translator 320 moves through position N-1/2 and shunts out the stepping relay 410 by connecting ground through its Contact 323, sequence switch contact 324, conductor 310, and sequence switch contact 317, to the wind ing of relay 305. The upper counting relay 3then extends the circuit to the lower count-V ing relay 2. The upper counting relay 2 becomes energized in position 0-1/2 and the upper counting relay 1 in position 1-1/2 of translator 309. The upper counting relay 0 energizes and opens the fundamental circuit when translator 320 closes contact 323 in position 2-1/2 and denergizes relay 410. When sequence switch 320 leaves position 2-1/2, relay 305 denergizes and closes at its right-hand armature and back contact a circuit to move the sequence switch 307 out ot' position 4 and into position 5, and the translator 320 is arrested in position 3, its circuit being broken at 322.

Upon the re'e'nergization of relay 305 sequence switch 307 is moved out ot position 5 into position 6, in which position a circuit is established from grounded battery, through the power magnet of the hundreds indicator 309, a sequence switch contact 325, and the right-hand front contact and armature ot relay 305 to ground. Under the con trol of its normal spring 326, indicator 300 is moved from position to position.

rEhe sequence switch 401 is driven out ot position 3 into position 10, whereupon the fundamental circuit energizing relays 410 and 305 is restablished at the outer contact, upper relay 0, and a circuit is closed from ground through the front contact and armature of stepping relay 410, sequence switch contact 435, conductor 436, and contact 437 o1 the depressed hundreds key 5, conductor 438, the winding ofthe lower counting relay 0, and conductor 414 to grounded battery.

TWhile switch 309is moving through position iT-1/2 ground is connected through indicator contact 327 and sequence switch contact 328 to conductor 316, resulting in the shunting out of stepping relay 410. The

- tact 326. It will be noted that these resting positions are numbered N, 0, 5, 1, 6, 2,7, 43,

3,14, 9. This irregular iiu-mbering of resting positions is necessitated by this; that when, c. g., the indicator is caused to move into its third resting position, not lamp No. 1, as is v.the case with the other indicator switches, but lamp No. 5 must he lighted.

In position 12 .of the Asequence switch 401 the Afundamental circuit is restablished, and relay 305 upon energization moves sequence switch 307 out of position 7 -into position 3,V

and locks itself up throughV its left-hand armature. A circuit is then closed from ground through the right-hand `armature and front contact of relay 305, sequence switch contact 330, and the power magnet of the tens indicator 310 to grounded battery. This indicator is moved out of position N, and under the control of its normal contact 331 `moved from position to position. TheY stepping relay 410 establishes a circuit from ground through its front contact and armature, sequence switch contact 460, conductor 461 the tens key 3, conductor 462, the armature and back contact of the upper counting` relay 3, the winding of the lower counting relay 3 and conductor 414 to grounded bat tery. The lower counting relay 3 prepares the circuit of the upper counting relay 3, and this counting relay becomes energized. when indicator 310 shunts out the stepping relay 410 in position N -1/2 by connecting ground through its contact 332 and sequence switch contact 333 to conductor 316. In position 0-1/2 of the tens indicator, the upper counting relay 2 becomes energized; in position 1-1/2 the upper counting relay l and in position 2-1/2 the upper counting relay 0 becomes energized, moves the sequence switch 401 out of position 12 into position 14, and opens the fundamental circuit. Relays 410 and 305 become denergized and the latter by moving sequence switch 307 out cil position 8 and into position 9, causes the arresting oit' indicator 310 in position 3.

As soon as tlieindicator 310 reaches position 0, a circuit is closed from ground through a contact 334 or this indicator, a contact 335 of the translator 320, a contact 336 of the hundreds indicator 309 (this indicator being in position 0), and the power magnet of indicator 309 to grounded bat- Y. tery. The indicator 309 is thus moved out of position 0v and under the control of its normal spring 326into position 5, whereupon its circuit being open at contaet'336 and the indicator stops. Another circuit is `closed from ground through contact 334, a

contact 3.70 of the translator 320. anda contact 371 and the power magnet of indicator out oi position -9 into position 10.whereupon a driving circuit is closecl through ,sequence switch contact 337 for the units indicator 311. This indicator is movedout of position N and is controlled in its further movement by normal spring 338.'V Relay 410 closes a circuit through sequence Vsvi/*itch con-A tact 463 and the Contact of the units hey 7 for the lower counting relay 7, and this prepares the circuit oit the upper ycounting relay 7. The upper `counting.rela-y 7`becomes energized when in position N-1/2, in-

dicatoi'311 closes contact 339, extending thus a ground through sequence switchcontact 340 to conductor 316, whereupon ,the stepping relai/410 is shunted. The upper counting relay 6 becomes energized in position (L1/2; the kuppercouiiting relay v5 in position '1.-1/2; the upper counting relay 4 in position 2-1/2; the uppercounting relay 43 in position 3-1/2; the upper counting relay 2 in position 4-1/2; the uppercounting relay 1 in position Y 5-1/2; and the .upper counting relay 0 in position 6-1/2 of indicator 311, The energization or the .upper counting relay 0 causes sequence switch 401 to move out of position 14 into position 1 and opens the fundamental circuit, whereuponY relays 410 and 305 become denergized and the latter'by moving sequence switch30i7 out of position 10 into position 11, causes the stopping of the units indicator in position 7. i

Upon the movement of the sequence switch 401 into position l, sequence Vswitch 106 is movedvout of position 11 into position 16.

1n position 11 .of sequence switch 307, ground is connected through sequence switch contact 341, contact 342 of the thousands indicator and a lamp 343 to grounded battery. Due to the closure of thesame contact 341, lamps 344, 345 and 346 will also'be lighted. The lighting of these lamps indicates to the B operator the number of the desired subscriber.V She thenY inserts plug 301 into a multiple jack 347 of this subscriber, whereupon a circuit is established from groundedV battery, through the wind# ing or' the cut-oli relay '0010i the called Relay V' 348 closes a circuit from ground through its front contact and armature, a

contact 349 and -the power magnet of se-` quence switch 307 to grounded battery,

Vist

whereupon the sequence switch is moved out of position 11 into position 13. When the sequence switch 307 moves out of position 11 and opens Contact 341, the lamps are eX- tinguished, and as soon as the sequence switch reaches position 12 and closes its contacts 350, 351, 369, 352 and 353, the thousands, hundreds, tens and units indicators and the translator are restored to normal.

In position 13 of sequence switch 307 a circuit is closed from ground through a ringing generator 355, a ringing relay 358, sequence switch contact 356, the called line circuit and sequence switch contact 357 to ground. When the called subscriber answers, relay 358 becomes denergized and closes a driving circuit from ground through sequence switch contact 359, the armature and front contact of relay 358 and the power magnet of sequence switch 307 to ground, for moving this sequence switch out of position 13 into position 15. The ringing current is then disconnected from the line and the connection is completed through sequence switch contacts 360 and 361. The supervisory relay SR becomes energized.

When disconnection is desired andthe calling and called subscribers restore their receivers, the two supervisory relays will be actuated. The A operator causes the release of selector 115 in the same manner as was above described. Upon. the release of the selector, relay 302 becomes denergized and closes a circuit from ground through its armature and back contact, a contact 362 of the power magnet of the sequence switch 307 to grounded battery, whereupon this sequence switch is moved out of position 15 and through position 17 into position 1. When the sequence switch moves through position `17 and closes a contact 363, a lamp 364 is lighted, indicating to the B operator that the subscribers are through conversing. She removes plug 301 from jack 347, causing thus the denergization of relay 348 and the called subscribers cut-olf relay.

lt will be obvious to those skilled in the art that instead of connecting the sender shown in Fig. 4 of the drawings directly to a trunk, under the control of a cord finder switch, such sender will preferably be selectively associated with any one of a plurality of trunks assigned for use in a manner set forth in Patent No. 1,168,319 of January 18, 1916. The indicators shown in Fig. 3 may also be provided in common for a plurality of trunks, and will preferably be associated with a selected trunk under the control of nder switches. trunk linder switches is disclosed in my Patent No. 1,232,944, of July 10, 1917. l if the thousands digit of the called number is even and one of the No. 0, 2, 4, 6 or 8 thousands keys is depressed, then in position 8 of sequence switch 401 the translator` Such an arrangement of' 320 is moved to positions 0 or 1, because at the sender the circuit is closed through one of the hundreds keys in one row with key 424 which, as above stated, are wired to the No. 0 and No. 1 counting relays. ln neither of these positions of the translator 320 is contact 370 closed, and therefore when the tens indicator 310 closes its contact 334, no circuit will be found to cause the driving of the thousands indicator 308, and this indicator will be left in positions 0, 2, 4, 6 or 8, depending on which of the thousands keys was depressed. As it will be seen, the numerical designation of these positions correspond to the numerical designations of the thousands keys. lf, however, as in the above described case, an odd number thousands key (l, 3, 5, 7, or 9) is depressed, then in position 8 of sequence switch 401, the translator 320 is caused to move to posi tions 2 or 3, because the hundreds keys in one row with key 425 are wired to the No. 2 and No. 3 counting relays. In both these positions of the translator, contact 370 is closed. ln view of the fact 'that the lefthand contacts of the odd number thousands keys are wired to the same counting relays to which the even number thousands keys are wired, the thousands indicator stops in the same positions as in the aforementioned case, when even number thousands keys were depressed. As soon, however, as the tens indicator closes contact 334, the circuit through the translator contact 370 and the thousands indicator contact 371 will be established, and the thousands indicator will be moved out of the even position into the next odd position which is of the same numerical designation as the depressed odd thousands key.

if an even or odd number thousands key is depressed and the hundreds digit is 0, 1, 2, 3 or 4, then in position 8 of the sequence switch 401, the translator 320 sends back one impulse or three impulses and is thus moved into positions 0, or 2. ln these positions of the translator contact 335 is leftv to send back two impulses, one in position l N-1/2 and the other in position -1/2 and stops in position 1. lf the No. 2 hundreds key is depressed the hundreds indicator sends back three impulses and stops in position 2, if the No. 3 hundreds key is cleiso pressed then the hundreds indicator' sends lator is permitted to send back four or two impulses and will thus stop in positions 3 or 1. 1n these positions contact 335 is closed. The hundreds indicator will stop in the same positions as above indicated, but as soon as the tens indicator closes contact 38st, the hundreds indicator will be moved to the next position indicated at the normal contact 326 of the hundreds indicator; that is to say,into positions 5, 6, 7 or 9, depending upon which of the hundreds keys 5 to 9 was depressed.

What is claimed is:

1. In combination, two selectively operable switching devices, a. variably Operable controlling device for said switchinodevices, means or adjusting said contrdlling device in accordance with a certain system of numerical designation, means responsive to the adjustment of said controlling` device for operating one of said switching devices in accordance with another system of numerical designation, and means responsive to the adjustment of said controlling device for operating the other one of said switching devices in accordance with-the iirst mentioned System of numerical designation.

f .Y devices in accordance with a system of numerical designation other than the decimal syste-mand means also responsive to the setting of said controlling device for operating the other of said selectively operable switching devices in accordance with the decimal numerical system of designation.

3. In combination, two selectively operable switching` devices, a sender for controlling the operation of said switching de- Y vices, anactuating member for said sender,

with thel other one oi said switching .65.

means for associating said sender with eitherone of said switching devices, means operable whenever the vsender is associated with one of the switching ldevices and in response to the operation -ofrsaid actuating member for controlling the movement of said switching deviceV a distance predetermined by said actuating member, and means operable whenever the sender is associated devices, 'and' responsive to vthe"acti'i'ation'of said member i'or controlling the movement l ot said last mentioned switching device to another distance than predetermined by the actuating member. 'j

4. In a telephone exchange system, a plurality of lines, means includingV a selector switch `for establishing aY connection between a calling and a called line, a sender comprising numbered actuating members,

arranged for adjustment in accordance with the number of the called line, means `re-V sponsive to the adjustment of said actuating members for causing 4said selector to take a' number of steps different from the numbers of the adjusted actuating members of said sender, number indicators ,movable under the control of'said sender, and means for permitting said number indicators to take a number of steps corresponding to the numbers of the adjusted actuating members.-

5. vIn' combination, two groups ofsw'itching devices, a variably operable sender for controlling theoperation of said switching',Y

devices, means responsiveto a certain adjustment of said sender for causing any one of the switching devices of one of said groups to traverse a distance identified by aV certain number of units of Va numerical system of designation, and means responsive'toj said certain adjustment of the senderv forl causing any of the switches of saidV second even numbers corresponding to the indications of the positions of said switching device, means r'esponsiveto theA operation of soi` an Yeven number actuating-member of said sendingrdevice for moving said switching.

device to a .position designated by a correspending even number, means responsive vto the operation of an odd number actuating membery of the sending devicefor moving the switching device to a position designated by an even number next lowest tothe odd number Ydesignation of the joperated actuating member, and meansV operative only when an odd number actuating `member has been-operated for advancingthe switching device to the next ,highest even number position. v v i 7. In combination, aV selectively operable switching device having positionsindicated by numbers `0 to 9, both' inclusive, a'variably,

operable sender having.' two setsiof actuating members numbered 0 to 9, bothinclusive, means responsive to theopera'tOn of an actuatin` member of one set andto the operation o 'any .one of the actuating menibers numbered y5- to e, Vteurinclusive,-`of the other set for moving said switching device into any one of the positions designated by numerals 0 to 4, both inclusive, and meansl operative only if the latter mentioned actuating members of the second set are operated for advancing the switching device to positions corresponding in numerical designation to the operated actuating members of the second set.

8. 1n combination, a selectively operable switching device having positions indicated by numbers 0 to 9, both inclusive, a sending device having actuating members numbered 0 to 9 both inclusive, means operative in response to the operation of any one of the actuating members numbered 0, 2, 4, 6 or 8,

Elm,

for moving said switching device into positlons O, 2, 4, 6 or 8 respectively, means operative in response to the operation of any one of the actuating members numbered 1,

3, 5, 7 or 9, Jfor moving said switching device into any one of the positions 0, 2, 4, 6 or 8, respectively, and means operative only when any one of the latter" mentioned actuating members is depressed for moving said switching device into any one of the positions 1, 3, 5, 7 or 9, respectively.

In witness whereof, I hereunto subscribe my name this 19th day of September, A. D., 1916.

ALBEN E. LUNDELL.

Gopies of this patent may be obtained for ve cents each, by addressing the Commissioner of Yatents, Washington, D. 1U. 

